Serino testified for a second day Tuesday about his investigation into the fatal shooting of the 17-year-old Miami teenager by George Zimmerman, a neighborhood watch volunteer.

O'Mara played the part of the interview where Zimmerman says the screams in the background of the 911 call "don't even sound like me." The defense says he didn't mean it was not him screaming, it just sounded unlike him.

Serino told O'Mara it didn't concern him that Zimmerman made that statement.

The state then objected to the defense bringing in Serino's meeting with Martin's father, Tracy Martin, saying it was beyond the scope of direct questioning. Nelson sustained the state's objection and O'Mara said the defense will call Serino as a defense witness and will ask about Tracy Martin's interview with him not recognizing his son's screams.

During redirect, de la Rionda played the non-emergency phone call where Zimmerman says "these a******* always get away" and "f****** punks" in an effort to show Zimmerman had ill-will, spite or anger. Serino said it didn't show ill will or spite, but then changed his answer and agreed to a point.

The state then played Zimmerman saying in one of his interviews that his wife "got scared" after their neighbor was burglarized so he started the Neighborhood Watch program.

"These guys always get away," Zimmerman said in the interview. De la Rionda asked Serino if it was "accurate he (Zimmerman) is profiling Trayvon Martin as a criminal?" The defense objected and Nelson sustained the objection.

Serino said there was no evidence Martin was committing a crime or was armed. In the recording of the interview, Zimmerman says he was "going in the same direction" as Martin. Serino says that's "following."

"You wanted to catch the bad guy, f****** punk kid, right?" Serino said in the audio interview to a subdued Zimmerman.

The state pointed out discrepancies in Zimmerman's recollections in what the non-emergency dispatcher asked him to do and why he walked behind the condos. De la Rionda replayed the video of Zimmerman, claiming to look for address, then shows the photo of the address on the townhome in front of him. De la Rionda pointed out the street name Zimmerman claimed not to know is the same street used to enter the subdivision, to which Serino agreed. Zimmerman told investigators he didn't know the street name attached to the numerical address seen where he left his vehicle.

De la Rionda then asked Serino about Zimmerman's claim he stretched out the arms of Martin, despite the first picture of Martin's body showing Martin's hands under his torso. Serino called Zimmerman's claim inconsistent with first photo.

The state also noted Serino had no DNA, ballistics, statement from Jeantel when he challenged Zimmerman in an interview.

During re-cross, O'Mara asked Serino if he had said the word "a*******" before and how Zimmerman said it in his interview, which Serino said didn't cause him any concern. Serino agreed with O'Mara that Zimmerman didn't "screech" words as de la Rionda did during his redirect of Serino.

O'Mara then asked about a "slim jim," which is used to break into vehicles, being found near the shooting scene. Serino said the burglary tool was found in the bushes behind one the witness' residence where Zimmerman says Martin may have hid, but it was not tied to the shooting case.

O'Mara asked Serino if he thought Zimmerman was following Martin and had Serino admit following someone is not illegal. Serino said he thinks Zimmerman was just outside his vehicle when he was told not to follow Martin, but Zimmerman's call suggests otherwise.

"In totality of the whole thing ... George Zimmerman was trying to do something int he same direction Trayvon Martin was going," Serino told O'Mara.

Serino agreed with O'Mara that Zimmerman had grounds to call non-emergency line about Martin, but Serino wouldn't have questioned the teen himself. He also said Zimmerman seemed "elated" that someone might have video of his encounter with Martin.

During re-redirect, de la Rionda asks, "are you saying ... it's against the law for someone to wear a hoodie at night?" The defense objected and de la Rionda rephrased his question. De la Rionda also reinforced with Serino that the "slim jim" found the bushes had nothing to do with the case.

Nelson then limited O'Mara's re-recross to five minutes. O'Mara suggested the lack of blood on Martin's hands explained because it was falling toward the earth or backing up into nose.

The state's next witness was Mark Osterman, neighbor/friend of Zimmerman. Osterman wrote a book trying to defend "the best friend I ever had." Osterman, a federal air marshal, looked directly at the jury as he testified, like law enforcement officers are trained to do.

Osterman quoted Zimmerman saying, "somehow I broke his grip on the gun when the guy grabbed between the grip and hammer." Zimmerman had previously only told police Martin reached for the gun, not that he actually grabbed it.

"I thought he had said he grabbed the gun," Osterman said. "I believe he said he grabbed the gun."

Osterman said Zimmerman "either broke contact or knocked Martin's hand away" from gun before pulling and firing it.

Osterman said he believes anyone who is not a convicted felon should have a firearm and said he encouraged Zimmerman to get a gun.

"Police are not always there," Osterman said. Osterman then described Zimmerman as "stunned, wide-eyed .. detached ... he wasn't answering questions ... just wanted to go home."